A collaborative web platform on tropical weed flora was created. Socially, a network of 780 actors interested in tropical weeds (researchers, teachers, students, technicians and farmers) was established. Individual and institutional capacity was built: 10 technician jobs created, 13 students supervised and 71 training sessions held in eight countries. Technologically, new tools for collaborative work (web portal, IDAO ‘IDentification Assistée par Ordinateur’ identification system, mobile applications for data collection and identification) were developed that respond with great efficiency to stakeholders’ needs. Technically, knowledge on 420 tropical weed species was assembled and c.10,000 field observations collected. Conceptually, a new approach of collaborative work and knowledge sharing in the field of agricultural science was demonstrated. A growing interest in other regions of the world was raised which will lead to the extension of the portal in other tropical areas.